Originally Posted by Djoker91
That's a great point. I find in tennis you can never swing as hard and fast as you can. You can only go 60-70%. At least for me. Then later on I can push 80 but that's it. If I try to go all in at 100 I wind up lost without a compass in shank city.
That really depends on one's skill and strategy at the time. Guys like Djokovic and Nadal frequently seemly go for 100% quite often, usually when there's a clear winner opportunity in sight (and they could afford to lose the point if they messed up). A good example of this is Djokovic vs Fed in the US Open semi (2010?) where he went all out and came back from multiple match points, and Fed complained that Djokovic played recklessly.